FreeBSD kernel kern code
kern_fork.c
Go to the documentation of this file.
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)kern_fork.c 8.6 (Berkeley) 4/8/94
37 */
38
39#include <sys/cdefs.h>
40__FBSDID("$FreeBSD$");
41
42#include "opt_ktrace.h"
43#include "opt_kstack_pages.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/bitstring.h>
48#include <sys/sysproto.h>
49#include <sys/eventhandler.h>
50#include <sys/fcntl.h>
51#include <sys/filedesc.h>
52#include <sys/jail.h>
53#include <sys/kernel.h>
54#include <sys/kthread.h>
55#include <sys/sysctl.h>
56#include <sys/lock.h>
57#include <sys/malloc.h>
58#include <sys/msan.h>
59#include <sys/mutex.h>
60#include <sys/priv.h>
61#include <sys/proc.h>
62#include <sys/procdesc.h>
63#include <sys/ptrace.h>
64#include <sys/racct.h>
65#include <sys/resourcevar.h>
66#include <sys/sched.h>
67#include <sys/syscall.h>
68#include <sys/vmmeter.h>
69#include <sys/vnode.h>
70#include <sys/acct.h>
71#include <sys/ktr.h>
72#include <sys/ktrace.h>
73#include <sys/unistd.h>
74#include <sys/sdt.h>
75#include <sys/sx.h>
76#include <sys/sysent.h>
77#include <sys/signalvar.h>
78
79#include <security/audit/audit.h>
80#include <security/mac/mac_framework.h>
81
82#include <vm/vm.h>
83#include <vm/pmap.h>
84#include <vm/vm_map.h>
85#include <vm/vm_extern.h>
86#include <vm/uma.h>
87
88#ifdef KDTRACE_HOOKS
89#include <sys/dtrace_bsd.h>
90dtrace_fork_func_t dtrace_fasttrap_fork;
91#endif
92
94SDT_PROBE_DEFINE3(proc, , , create, "struct proc *", "struct proc *", "int");
95
96#ifndef _SYS_SYSPROTO_H_
97struct fork_args {
98 int dummy;
99};
100#endif
101
102/* ARGSUSED */
103int
104sys_fork(struct thread *td, struct fork_args *uap)
105{
106 struct fork_req fr;
107 int error, pid;
108
109 bzero(&fr, sizeof(fr));
110 fr.fr_flags = RFFDG | RFPROC;
111 fr.fr_pidp = &pid;
112 error = fork1(td, &fr);
113 if (error == 0) {
114 td->td_retval[0] = pid;
115 td->td_retval[1] = 0;
116 }
117 return (error);
118}
119
120/* ARGUSED */
121int
122sys_pdfork(struct thread *td, struct pdfork_args *uap)
123{
124 struct fork_req fr;
125 int error, fd, pid;
126
127 bzero(&fr, sizeof(fr));
128 fr.fr_flags = RFFDG | RFPROC | RFPROCDESC;
129 fr.fr_pidp = &pid;
130 fr.fr_pd_fd = &fd;
131 fr.fr_pd_flags = uap->flags;
132 AUDIT_ARG_FFLAGS(uap->flags);
133 /*
134 * It is necessary to return fd by reference because 0 is a valid file
135 * descriptor number, and the child needs to be able to distinguish
136 * itself from the parent using the return value.
137 */
138 error = fork1(td, &fr);
139 if (error == 0) {
140 td->td_retval[0] = pid;
141 td->td_retval[1] = 0;
142 error = copyout(&fd, uap->fdp, sizeof(fd));
143 }
144 return (error);
145}
146
147/* ARGSUSED */
148int
149sys_vfork(struct thread *td, struct vfork_args *uap)
150{
151 struct fork_req fr;
152 int error, pid;
153
154 bzero(&fr, sizeof(fr));
155 fr.fr_flags = RFFDG | RFPROC | RFPPWAIT | RFMEM;
156 fr.fr_pidp = &pid;
157 error = fork1(td, &fr);
158 if (error == 0) {
159 td->td_retval[0] = pid;
160 td->td_retval[1] = 0;
161 }
162 return (error);
163}
164
165int
166sys_rfork(struct thread *td, struct rfork_args *uap)
167{
168 struct fork_req fr;
169 int error, pid;
170
171 /* Don't allow kernel-only flags. */
172 if ((uap->flags & RFKERNELONLY) != 0)
173 return (EINVAL);
174 /* RFSPAWN must not appear with others */
175 if ((uap->flags & RFSPAWN) != 0 && uap->flags != RFSPAWN)
176 return (EINVAL);
177
178 AUDIT_ARG_FFLAGS(uap->flags);
179 bzero(&fr, sizeof(fr));
180 if ((uap->flags & RFSPAWN) != 0) {
181 fr.fr_flags = RFFDG | RFPROC | RFPPWAIT | RFMEM;
182 fr.fr_flags2 = FR2_DROPSIG_CAUGHT;
183 } else {
184 fr.fr_flags = uap->flags;
185 }
186 fr.fr_pidp = &pid;
187 error = fork1(td, &fr);
188 if (error == 0) {
189 td->td_retval[0] = pid;
190 td->td_retval[1] = 0;
191 }
192 return (error);
193}
194
195int __exclusive_cache_line nprocs = 1; /* process 0 */
196int lastpid = 0;
197SYSCTL_INT(_kern, OID_AUTO, lastpid, CTLFLAG_RD, &lastpid, 0,
198 "Last used PID");
199
200/*
201 * Random component to lastpid generation. We mix in a random factor to make
202 * it a little harder to predict. We sanity check the modulus value to avoid
203 * doing it in critical paths. Don't let it be too small or we pointlessly
204 * waste randomness entropy, and don't let it be impossibly large. Using a
205 * modulus that is too big causes a LOT more process table scans and slows
206 * down fork processing as the pidchecked caching is defeated.
207 */
208static int randompid = 0;
209
210static int
211sysctl_kern_randompid(SYSCTL_HANDLER_ARGS)
212{
213 int error, pid;
214
215 error = sysctl_wire_old_buffer(req, sizeof(int));
216 if (error != 0)
217 return(error);
218 sx_xlock(&allproc_lock);
219 pid = randompid;
220 error = sysctl_handle_int(oidp, &pid, 0, req);
221 if (error == 0 && req->newptr != NULL) {
222 if (pid == 0)
223 randompid = 0;
224 else if (pid == 1)
225 /* generate a random PID modulus between 100 and 1123 */
226 randompid = 100 + arc4random() % 1024;
227 else if (pid < 0 || pid > pid_max - 100)
228 /* out of range */
229 randompid = pid_max - 100;
230 else if (pid < 100)
231 /* Make it reasonable */
232 randompid = 100;
233 else
234 randompid = pid;
235 }
236 sx_xunlock(&allproc_lock);
237 return (error);
238}
239
240SYSCTL_PROC(_kern, OID_AUTO, randompid,
241 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
243 "Random PID modulus. Special values: 0: disable, 1: choose random value");
244
245extern bitstr_t proc_id_pidmap;
246extern bitstr_t proc_id_grpidmap;
247extern bitstr_t proc_id_sessidmap;
248extern bitstr_t proc_id_reapmap;
249
250/*
251 * Find an unused process ID
252 *
253 * If RFHIGHPID is set (used during system boot), do not allocate
254 * low-numbered pids.
255 */
256static int
258{
259 pid_t result;
260 int trypid, random;
261
262 /*
263 * Avoid calling arc4random with procid_lock held.
264 */
265 random = 0;
266 if (__predict_false(randompid))
267 random = arc4random() % randompid;
268
269 mtx_lock(&procid_lock);
270
271 trypid = lastpid + 1;
272 if (flags & RFHIGHPID) {
273 if (trypid < 10)
274 trypid = 10;
275 } else {
276 trypid += random;
277 }
278retry:
279 if (trypid >= pid_max)
280 trypid = 2;
281
282 bit_ffc_at(&proc_id_pidmap, trypid, pid_max, &result);
283 if (result == -1) {
284 KASSERT(trypid != 2, ("unexpectedly ran out of IDs"));
285 trypid = 2;
286 goto retry;
287 }
288 if (bit_test(&proc_id_grpidmap, result) ||
289 bit_test(&proc_id_sessidmap, result) ||
290 bit_test(&proc_id_reapmap, result)) {
291 trypid = result + 1;
292 goto retry;
293 }
294
295 /*
296 * RFHIGHPID does not mess with the lastpid counter during boot.
297 */
298 if ((flags & RFHIGHPID) == 0)
299 lastpid = result;
300
301 bit_set(&proc_id_pidmap, result);
302 mtx_unlock(&procid_lock);
303
304 return (result);
305}
306
307static int
308fork_norfproc(struct thread *td, int flags)
309{
310 int error;
311 struct proc *p1;
312
313 KASSERT((flags & RFPROC) == 0,
314 ("fork_norfproc called with RFPROC set"));
315 p1 = td->td_proc;
316
317 /*
318 * Quiesce other threads if necessary. If RFMEM is not specified we
319 * must ensure that other threads do not concurrently create a second
320 * process sharing the vmspace, see vmspace_unshare().
321 */
322 if ((p1->p_flag & (P_HADTHREADS | P_SYSTEM)) == P_HADTHREADS &&
323 ((flags & (RFCFDG | RFFDG)) != 0 || (flags & RFMEM) == 0)) {
324 PROC_LOCK(p1);
325 if (thread_single(p1, SINGLE_BOUNDARY)) {
326 PROC_UNLOCK(p1);
327 return (ERESTART);
328 }
329 PROC_UNLOCK(p1);
330 }
331
332 error = vm_forkproc(td, NULL, NULL, NULL, flags);
333 if (error)
334 goto fail;
335
336 /*
337 * Close all file descriptors.
338 */
339 if (flags & RFCFDG) {
340 struct filedesc *fdtmp;
341 struct pwddesc *pdtmp;
342 pdtmp = pdinit(td->td_proc->p_pd, false);
343 fdtmp = fdinit();
344 pdescfree(td);
345 fdescfree(td);
346 p1->p_fd = fdtmp;
347 p1->p_pd = pdtmp;
348 }
349
350 /*
351 * Unshare file descriptors (from parent).
352 */
353 if (flags & RFFDG) {
354 fdunshare(td);
355 pdunshare(td);
356 }
357
358fail:
359 if ((p1->p_flag & (P_HADTHREADS | P_SYSTEM)) == P_HADTHREADS &&
360 ((flags & (RFCFDG | RFFDG)) != 0 || (flags & RFMEM) == 0)) {
361 PROC_LOCK(p1);
362 thread_single_end(p1, SINGLE_BOUNDARY);
363 PROC_UNLOCK(p1);
364 }
365 return (error);
366}
367
368static void
369do_fork(struct thread *td, struct fork_req *fr, struct proc *p2, struct thread *td2,
370 struct vmspace *vm2, struct file *fp_procdesc)
371{
372 struct proc *p1, *pptr;
373 struct filedesc *fd;
374 struct filedesc_to_leader *fdtol;
375 struct pwddesc *pd;
376 struct sigacts *newsigacts;
377
378 p1 = td->td_proc;
379
380 PROC_LOCK(p1);
381 bcopy(&p1->p_startcopy, &p2->p_startcopy,
382 __rangeof(struct proc, p_startcopy, p_endcopy));
383 pargs_hold(p2->p_args);
384 PROC_UNLOCK(p1);
385
386 bzero(&p2->p_startzero,
387 __rangeof(struct proc, p_startzero, p_endzero));
388
389 /* Tell the prison that we exist. */
390 prison_proc_hold(p2->p_ucred->cr_prison);
391
392 p2->p_state = PRS_NEW; /* protect against others */
393 p2->p_pid = fork_findpid(fr->fr_flags);
394 AUDIT_ARG_PID(p2->p_pid);
395 TSFORK(p2->p_pid, p1->p_pid);
396
397 sx_xlock(&allproc_lock);
398 LIST_INSERT_HEAD(&allproc, p2, p_list);
399 allproc_gen++;
400 sx_xunlock(&allproc_lock);
401
402 sx_xlock(PIDHASHLOCK(p2->p_pid));
403 LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
404 sx_xunlock(PIDHASHLOCK(p2->p_pid));
405
406 tidhash_add(td2);
407
408 /*
409 * Malloc things while we don't hold any locks.
410 */
411 if (fr->fr_flags & RFSIGSHARE)
412 newsigacts = NULL;
413 else
414 newsigacts = sigacts_alloc();
415
416 /*
417 * Copy filedesc.
418 */
419 if (fr->fr_flags & RFCFDG) {
420 pd = pdinit(p1->p_pd, false);
421 fd = fdinit();
422 fdtol = NULL;
423 } else if (fr->fr_flags & RFFDG) {
424 if (fr->fr_flags2 & FR2_SHARE_PATHS)
425 pd = pdshare(p1->p_pd);
426 else
427 pd = pdcopy(p1->p_pd);
428 fd = fdcopy(p1->p_fd);
429 fdtol = NULL;
430 } else {
431 if (fr->fr_flags2 & FR2_SHARE_PATHS)
432 pd = pdcopy(p1->p_pd);
433 else
434 pd = pdshare(p1->p_pd);
435 fd = fdshare(p1->p_fd);
436 if (p1->p_fdtol == NULL)
437 p1->p_fdtol = filedesc_to_leader_alloc(NULL, NULL,
438 p1->p_leader);
439 if ((fr->fr_flags & RFTHREAD) != 0) {
440 /*
441 * Shared file descriptor table, and shared
442 * process leaders.
443 */
444 fdtol = p1->p_fdtol;
445 FILEDESC_XLOCK(p1->p_fd);
446 fdtol->fdl_refcount++;
447 FILEDESC_XUNLOCK(p1->p_fd);
448 } else {
449 /*
450 * Shared file descriptor table, and different
451 * process leaders.
452 */
453 fdtol = filedesc_to_leader_alloc(p1->p_fdtol,
454 p1->p_fd, p2);
455 }
456 }
457 /*
458 * Make a proc table entry for the new process.
459 * Start by zeroing the section of proc that is zero-initialized,
460 * then copy the section that is copied directly from the parent.
461 */
462
463 PROC_LOCK(p2);
464 PROC_LOCK(p1);
465
466 bzero(&td2->td_startzero,
467 __rangeof(struct thread, td_startzero, td_endzero));
468
469 bcopy(&td->td_startcopy, &td2->td_startcopy,
470 __rangeof(struct thread, td_startcopy, td_endcopy));
471
472 bcopy(&p2->p_comm, &td2->td_name, sizeof(td2->td_name));
473 td2->td_sigstk = td->td_sigstk;
474 td2->td_flags = TDF_INMEM;
475 td2->td_lend_user_pri = PRI_MAX;
476
477#ifdef VIMAGE
478 td2->td_vnet = NULL;
479 td2->td_vnet_lpush = NULL;
480#endif
481
482 /*
483 * Allow the scheduler to initialize the child.
484 */
485 thread_lock(td);
486 sched_fork(td, td2);
487 /*
488 * Request AST to check for TDP_RFPPWAIT. Do it here
489 * to avoid calling thread_lock() again.
490 */
491 if ((fr->fr_flags & RFPPWAIT) != 0)
492 td->td_flags |= TDF_ASTPENDING;
493 thread_unlock(td);
494
495 /*
496 * Duplicate sub-structures as needed.
497 * Increase reference counts on shared objects.
498 */
499 p2->p_flag = P_INMEM;
500 p2->p_flag2 = p1->p_flag2 & (P2_ASLR_DISABLE | P2_ASLR_ENABLE |
501 P2_ASLR_IGNSTART | P2_NOTRACE | P2_NOTRACE_EXEC |
502 P2_PROTMAX_ENABLE | P2_PROTMAX_DISABLE | P2_TRAPCAP |
503 P2_STKGAP_DISABLE | P2_STKGAP_DISABLE_EXEC | P2_NO_NEW_PRIVS |
504 P2_WXORX_DISABLE | P2_WXORX_ENABLE_EXEC);
505 p2->p_swtick = ticks;
506 if (p1->p_flag & P_PROFIL)
507 startprofclock(p2);
508
509 if (fr->fr_flags & RFSIGSHARE) {
510 p2->p_sigacts = sigacts_hold(p1->p_sigacts);
511 } else {
512 sigacts_copy(newsigacts, p1->p_sigacts);
513 p2->p_sigacts = newsigacts;
514 if ((fr->fr_flags2 & (FR2_DROPSIG_CAUGHT | FR2_KPROC)) != 0) {
515 mtx_lock(&p2->p_sigacts->ps_mtx);
516 if ((fr->fr_flags2 & FR2_DROPSIG_CAUGHT) != 0)
517 sig_drop_caught(p2);
518 if ((fr->fr_flags2 & FR2_KPROC) != 0)
519 p2->p_sigacts->ps_flag |= PS_NOCLDWAIT;
520 mtx_unlock(&p2->p_sigacts->ps_mtx);
521 }
522 }
523
524 if (fr->fr_flags & RFTSIGZMB)
525 p2->p_sigparent = RFTSIGNUM(fr->fr_flags);
526 else if (fr->fr_flags & RFLINUXTHPN)
527 p2->p_sigparent = SIGUSR1;
528 else
529 p2->p_sigparent = SIGCHLD;
530
531 if ((fr->fr_flags2 & FR2_KPROC) != 0) {
532 p2->p_flag |= P_SYSTEM | P_KPROC;
533 td2->td_pflags |= TDP_KTHREAD;
534 }
535
536 p2->p_textvp = p1->p_textvp;
537 p2->p_textdvp = p1->p_textdvp;
538 p2->p_fd = fd;
539 p2->p_fdtol = fdtol;
540 p2->p_pd = pd;
541
542 if (p1->p_flag2 & P2_INHERIT_PROTECTED) {
543 p2->p_flag |= P_PROTECTED;
544 p2->p_flag2 |= P2_INHERIT_PROTECTED;
545 }
546
547 /*
548 * p_limit is copy-on-write. Bump its refcount.
549 */
550 lim_fork(p1, p2);
551
552 thread_cow_get_proc(td2, p2);
553
554 pstats_fork(p1->p_stats, p2->p_stats);
555
556 PROC_UNLOCK(p1);
557 PROC_UNLOCK(p2);
558
559 /*
560 * Bump references to the text vnode and directory, and copy
561 * the hardlink name.
562 */
563 if (p2->p_textvp != NULL)
564 vrefact(p2->p_textvp);
565 if (p2->p_textdvp != NULL)
566 vrefact(p2->p_textdvp);
567 p2->p_binname = p1->p_binname == NULL ? NULL :
568 strdup(p1->p_binname, M_PARGS);
569
570 /*
571 * Set up linkage for kernel based threading.
572 */
573 if ((fr->fr_flags & RFTHREAD) != 0) {
574 mtx_lock(&ppeers_lock);
575 p2->p_peers = p1->p_peers;
576 p1->p_peers = p2;
577 p2->p_leader = p1->p_leader;
578 mtx_unlock(&ppeers_lock);
579 PROC_LOCK(p1->p_leader);
580 if ((p1->p_leader->p_flag & P_WEXIT) != 0) {
581 PROC_UNLOCK(p1->p_leader);
582 /*
583 * The task leader is exiting, so process p1 is
584 * going to be killed shortly. Since p1 obviously
585 * isn't dead yet, we know that the leader is either
586 * sending SIGKILL's to all the processes in this
587 * task or is sleeping waiting for all the peers to
588 * exit. We let p1 complete the fork, but we need
589 * to go ahead and kill the new process p2 since
590 * the task leader may not get a chance to send
591 * SIGKILL to it. We leave it on the list so that
592 * the task leader will wait for this new process
593 * to commit suicide.
594 */
595 PROC_LOCK(p2);
596 kern_psignal(p2, SIGKILL);
597 PROC_UNLOCK(p2);
598 } else
599 PROC_UNLOCK(p1->p_leader);
600 } else {
601 p2->p_peers = NULL;
602 p2->p_leader = p2;
603 }
604
605 sx_xlock(&proctree_lock);
606 PGRP_LOCK(p1->p_pgrp);
607 PROC_LOCK(p2);
608 PROC_LOCK(p1);
609
610 /*
611 * Preserve some more flags in subprocess. P_PROFIL has already
612 * been preserved.
613 */
614 p2->p_flag |= p1->p_flag & P_SUGID;
615 td2->td_pflags |= (td->td_pflags & (TDP_ALTSTACK | TDP_SIGFASTBLOCK));
616 SESS_LOCK(p1->p_session);
617 if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
618 p2->p_flag |= P_CONTROLT;
619 SESS_UNLOCK(p1->p_session);
620 if (fr->fr_flags & RFPPWAIT)
621 p2->p_flag |= P_PPWAIT;
622
623 p2->p_pgrp = p1->p_pgrp;
624 LIST_INSERT_AFTER(p1, p2, p_pglist);
625 PGRP_UNLOCK(p1->p_pgrp);
626 LIST_INIT(&p2->p_children);
627 LIST_INIT(&p2->p_orphans);
628
629 callout_init_mtx(&p2->p_itcallout, &p2->p_mtx, 0);
630 TAILQ_INIT(&p2->p_kqtim_stop);
631
632 /*
633 * This begins the section where we must prevent the parent
634 * from being swapped.
635 */
636 _PHOLD(p1);
637 PROC_UNLOCK(p1);
638
639 /*
640 * Attach the new process to its parent.
641 *
642 * If RFNOWAIT is set, the newly created process becomes a child
643 * of init. This effectively disassociates the child from the
644 * parent.
645 */
646 if ((fr->fr_flags & RFNOWAIT) != 0) {
647 pptr = p1->p_reaper;
648 p2->p_reaper = pptr;
649 } else {
650 p2->p_reaper = (p1->p_treeflag & P_TREE_REAPER) != 0 ?
651 p1 : p1->p_reaper;
652 pptr = p1;
653 }
654 p2->p_pptr = pptr;
655 p2->p_oppid = pptr->p_pid;
656 LIST_INSERT_HEAD(&pptr->p_children, p2, p_sibling);
657 LIST_INIT(&p2->p_reaplist);
658 LIST_INSERT_HEAD(&p2->p_reaper->p_reaplist, p2, p_reapsibling);
659 if (p2->p_reaper == p1 && p1 != initproc) {
660 p2->p_reapsubtree = p2->p_pid;
661 proc_id_set_cond(PROC_ID_REAP, p2->p_pid);
662 }
663 sx_xunlock(&proctree_lock);
664
665 /* Inform accounting that we have forked. */
666 p2->p_acflag = AFORK;
667 PROC_UNLOCK(p2);
668
669#ifdef KTRACE
670 ktrprocfork(p1, p2);
671#endif
672
673 /*
674 * Finish creating the child process. It will return via a different
675 * execution path later. (ie: directly into user mode)
676 */
677 vm_forkproc(td, p2, td2, vm2, fr->fr_flags);
678
679 if (fr->fr_flags == (RFFDG | RFPROC)) {
680 VM_CNT_INC(v_forks);
681 VM_CNT_ADD(v_forkpages, p2->p_vmspace->vm_dsize +
682 p2->p_vmspace->vm_ssize);
683 } else if (fr->fr_flags == (RFFDG | RFPROC | RFPPWAIT | RFMEM)) {
684 VM_CNT_INC(v_vforks);
685 VM_CNT_ADD(v_vforkpages, p2->p_vmspace->vm_dsize +
686 p2->p_vmspace->vm_ssize);
687 } else if (p1 == &proc0) {
688 VM_CNT_INC(v_kthreads);
689 VM_CNT_ADD(v_kthreadpages, p2->p_vmspace->vm_dsize +
690 p2->p_vmspace->vm_ssize);
691 } else {
692 VM_CNT_INC(v_rforks);
693 VM_CNT_ADD(v_rforkpages, p2->p_vmspace->vm_dsize +
694 p2->p_vmspace->vm_ssize);
695 }
696
697 /*
698 * Associate the process descriptor with the process before anything
699 * can happen that might cause that process to need the descriptor.
700 * However, don't do this until after fork(2) can no longer fail.
701 */
702 if (fr->fr_flags & RFPROCDESC)
703 procdesc_new(p2, fr->fr_pd_flags);
704
705 /*
706 * Both processes are set up, now check if any loadable modules want
707 * to adjust anything.
708 */
709 EVENTHANDLER_DIRECT_INVOKE(process_fork, p1, p2, fr->fr_flags);
710
711 /*
712 * Set the child start time and mark the process as being complete.
713 */
714 PROC_LOCK(p2);
715 PROC_LOCK(p1);
716 microuptime(&p2->p_stats->p_start);
717 PROC_SLOCK(p2);
718 p2->p_state = PRS_NORMAL;
719 PROC_SUNLOCK(p2);
720
721#ifdef KDTRACE_HOOKS
722 /*
723 * Tell the DTrace fasttrap provider about the new process so that any
724 * tracepoints inherited from the parent can be removed. We have to do
725 * this only after p_state is PRS_NORMAL since the fasttrap module will
726 * use pfind() later on.
727 */
728 if ((fr->fr_flags & RFMEM) == 0 && dtrace_fasttrap_fork)
729 dtrace_fasttrap_fork(p1, p2);
730#endif
731 if (fr->fr_flags & RFPPWAIT) {
732 td->td_pflags |= TDP_RFPPWAIT;
733 td->td_rfppwait_p = p2;
734 td->td_dbgflags |= TDB_VFORK;
735 }
736 PROC_UNLOCK(p2);
737
738 /*
739 * Tell any interested parties about the new process.
740 */
741 knote_fork(p1->p_klist, p2->p_pid);
742
743 /*
744 * Now can be swapped.
745 */
746 _PRELE(p1);
747 PROC_UNLOCK(p1);
748 SDT_PROBE3(proc, , , create, p2, p1, fr->fr_flags);
749
750 if (fr->fr_flags & RFPROCDESC) {
751 procdesc_finit(p2->p_procdesc, fp_procdesc);
752 fdrop(fp_procdesc, td);
753 }
754
755 /*
756 * Speculative check for PTRACE_FORK. PTRACE_FORK is not
757 * synced with forks in progress so it is OK if we miss it
758 * if being set atm.
759 */
760 if ((p1->p_ptevents & PTRACE_FORK) != 0) {
761 sx_xlock(&proctree_lock);
762 PROC_LOCK(p2);
763
764 /*
765 * p1->p_ptevents & p1->p_pptr are protected by both
766 * process and proctree locks for modifications,
767 * so owning proctree_lock allows the race-free read.
768 */
769 if ((p1->p_ptevents & PTRACE_FORK) != 0) {
770 /*
771 * Arrange for debugger to receive the fork event.
772 *
773 * We can report PL_FLAG_FORKED regardless of
774 * P_FOLLOWFORK settings, but it does not make a sense
775 * for runaway child.
776 */
777 td->td_dbgflags |= TDB_FORK;
778 td->td_dbg_forked = p2->p_pid;
779 td2->td_dbgflags |= TDB_STOPATFORK;
780 proc_set_traced(p2, true);
781 CTR2(KTR_PTRACE,
782 "do_fork: attaching to new child pid %d: oppid %d",
783 p2->p_pid, p2->p_oppid);
784 proc_reparent(p2, p1->p_pptr, false);
785 }
786 PROC_UNLOCK(p2);
787 sx_xunlock(&proctree_lock);
788 }
789
790 racct_proc_fork_done(p2);
791
792 if ((fr->fr_flags & RFSTOPPED) == 0) {
793 if (fr->fr_pidp != NULL)
794 *fr->fr_pidp = p2->p_pid;
795 /*
796 * If RFSTOPPED not requested, make child runnable and
797 * add to run queue.
798 */
799 thread_lock(td2);
800 TD_SET_CAN_RUN(td2);
801 sched_add(td2, SRQ_BORING);
802 } else {
803 *fr->fr_procp = p2;
804 }
805}
806
807void
808fork_rfppwait(struct thread *td)
809{
810 struct proc *p, *p2;
811
812 MPASS(td->td_pflags & TDP_RFPPWAIT);
813
814 p = td->td_proc;
815 /*
816 * Preserve synchronization semantics of vfork. If
817 * waiting for child to exec or exit, fork set
818 * P_PPWAIT on child, and there we sleep on our proc
819 * (in case of exit).
820 *
821 * Do it after the ptracestop() above is finished, to
822 * not block our debugger until child execs or exits
823 * to finish vfork wait.
824 */
825 td->td_pflags &= ~TDP_RFPPWAIT;
826 p2 = td->td_rfppwait_p;
827again:
828 PROC_LOCK(p2);
829 while (p2->p_flag & P_PPWAIT) {
830 PROC_LOCK(p);
832 PROC_UNLOCK(p2);
834 PROC_UNLOCK(p);
835 goto again;
836 } else {
837 PROC_UNLOCK(p);
838 }
839 cv_timedwait(&p2->p_pwait, &p2->p_mtx, hz);
840 }
841 PROC_UNLOCK(p2);
842
843 if (td->td_dbgflags & TDB_VFORK) {
844 PROC_LOCK(p);
845 if (p->p_ptevents & PTRACE_VFORK)
846 ptracestop(td, SIGTRAP, NULL);
847 td->td_dbgflags &= ~TDB_VFORK;
848 PROC_UNLOCK(p);
849 }
850}
851
852int
853fork1(struct thread *td, struct fork_req *fr)
854{
855 struct proc *p1, *newproc;
856 struct thread *td2;
857 struct vmspace *vm2;
858 struct ucred *cred;
859 struct file *fp_procdesc;
860 vm_ooffset_t mem_charged;
861 int error, nprocs_new;
862 static int curfail;
863 static struct timeval lastfail;
864 int flags, pages;
865
866 flags = fr->fr_flags;
867 pages = fr->fr_pages;
868
869 if ((flags & RFSTOPPED) != 0)
870 MPASS(fr->fr_procp != NULL && fr->fr_pidp == NULL);
871 else
872 MPASS(fr->fr_procp == NULL);
873
874 /* Check for the undefined or unimplemented flags. */
875 if ((flags & ~(RFFLAGS | RFTSIGFLAGS(RFTSIGMASK))) != 0)
876 return (EINVAL);
877
878 /* Signal value requires RFTSIGZMB. */
879 if ((flags & RFTSIGFLAGS(RFTSIGMASK)) != 0 && (flags & RFTSIGZMB) == 0)
880 return (EINVAL);
881
882 /* Can't copy and clear. */
883 if ((flags & (RFFDG|RFCFDG)) == (RFFDG|RFCFDG))
884 return (EINVAL);
885
886 /* Check the validity of the signal number. */
887 if ((flags & RFTSIGZMB) != 0 && (u_int)RFTSIGNUM(flags) > _SIG_MAXSIG)
888 return (EINVAL);
889
890 if ((flags & RFPROCDESC) != 0) {
891 /* Can't not create a process yet get a process descriptor. */
892 if ((flags & RFPROC) == 0)
893 return (EINVAL);
894
895 /* Must provide a place to put a procdesc if creating one. */
896 if (fr->fr_pd_fd == NULL)
897 return (EINVAL);
898
899 /* Check if we are using supported flags. */
900 if ((fr->fr_pd_flags & ~PD_ALLOWED_AT_FORK) != 0)
901 return (EINVAL);
902 }
903
904 p1 = td->td_proc;
905
906 /*
907 * Here we don't create a new process, but we divorce
908 * certain parts of a process from itself.
909 */
910 if ((flags & RFPROC) == 0) {
911 if (fr->fr_procp != NULL)
912 *fr->fr_procp = NULL;
913 else if (fr->fr_pidp != NULL)
914 *fr->fr_pidp = 0;
915 return (fork_norfproc(td, flags));
916 }
917
918 fp_procdesc = NULL;
919 newproc = NULL;
920 vm2 = NULL;
921
922 /*
923 * Increment the nprocs resource before allocations occur.
924 * Although process entries are dynamically created, we still
925 * keep a global limit on the maximum number we will
926 * create. There are hard-limits as to the number of processes
927 * that can run, established by the KVA and memory usage for
928 * the process data.
929 *
930 * Don't allow a nonprivileged user to use the last ten
931 * processes; don't let root exceed the limit.
932 */
933 nprocs_new = atomic_fetchadd_int(&nprocs, 1) + 1;
934 if (nprocs_new >= maxproc - 10) {
935 if (priv_check_cred(td->td_ucred, PRIV_MAXPROC) != 0 ||
936 nprocs_new >= maxproc) {
937 error = EAGAIN;
938 sx_xlock(&allproc_lock);
939 if (ppsratecheck(&lastfail, &curfail, 1)) {
940 printf("maxproc limit exceeded by uid %u "
941 "(pid %d); see tuning(7) and "
942 "login.conf(5)\n",
943 td->td_ucred->cr_ruid, p1->p_pid);
944 }
945 sx_xunlock(&allproc_lock);
946 goto fail2;
947 }
948 }
949
950 /*
951 * If required, create a process descriptor in the parent first; we
952 * will abandon it if something goes wrong. We don't finit() until
953 * later.
954 */
955 if (flags & RFPROCDESC) {
956 error = procdesc_falloc(td, &fp_procdesc, fr->fr_pd_fd,
957 fr->fr_pd_flags, fr->fr_pd_fcaps);
958 if (error != 0)
959 goto fail2;
960 AUDIT_ARG_FD(*fr->fr_pd_fd);
961 }
962
963 mem_charged = 0;
964 if (pages == 0)
965 pages = kstack_pages;
966 /* Allocate new proc. */
967 newproc = uma_zalloc(proc_zone, M_WAITOK);
968 td2 = FIRST_THREAD_IN_PROC(newproc);
969 if (td2 == NULL) {
970 td2 = thread_alloc(pages);
971 if (td2 == NULL) {
972 error = ENOMEM;
973 goto fail2;
974 }
975 proc_linkup(newproc, td2);
976 } else {
978 if (td2->td_kstack == 0 || td2->td_kstack_pages != pages) {
979 if (td2->td_kstack != 0)
980 vm_thread_dispose(td2);
981 if (!thread_alloc_stack(td2, pages)) {
982 error = ENOMEM;
983 goto fail2;
984 }
985 }
986 }
987
988 if ((flags & RFMEM) == 0) {
989 vm2 = vmspace_fork(p1->p_vmspace, &mem_charged);
990 if (vm2 == NULL) {
991 error = ENOMEM;
992 goto fail2;
993 }
994 if (!swap_reserve(mem_charged)) {
995 /*
996 * The swap reservation failed. The accounting
997 * from the entries of the copied vm2 will be
998 * subtracted in vmspace_free(), so force the
999 * reservation there.
1000 */
1001 swap_reserve_force(mem_charged);
1002 error = ENOMEM;
1003 goto fail2;
1004 }
1005 } else
1006 vm2 = NULL;
1007
1008 /*
1009 * XXX: This is ugly; when we copy resource usage, we need to bump
1010 * per-cred resource counters.
1011 */
1012 proc_set_cred_init(newproc, td->td_ucred);
1013
1014 /*
1015 * Initialize resource accounting for the child process.
1016 */
1017 error = racct_proc_fork(p1, newproc);
1018 if (error != 0) {
1019 error = EAGAIN;
1020 goto fail1;
1021 }
1022
1023#ifdef MAC
1024 mac_proc_init(newproc);
1025#endif
1026 newproc->p_klist = knlist_alloc(&newproc->p_mtx);
1027 STAILQ_INIT(&newproc->p_ktr);
1028
1029 /*
1030 * Increment the count of procs running with this uid. Don't allow
1031 * a nonprivileged user to exceed their current limit.
1032 */
1033 cred = td->td_ucred;
1034 if (!chgproccnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPROC))) {
1035 if (priv_check_cred(cred, PRIV_PROC_LIMIT) != 0)
1036 goto fail0;
1037 chgproccnt(cred->cr_ruidinfo, 1, 0);
1038 }
1039
1040 do_fork(td, fr, newproc, td2, vm2, fp_procdesc);
1041 return (0);
1042fail0:
1043 error = EAGAIN;
1044#ifdef MAC
1045 mac_proc_destroy(newproc);
1046#endif
1047 racct_proc_exit(newproc);
1048fail1:
1049 proc_unset_cred(newproc);
1050fail2:
1051 if (vm2 != NULL)
1052 vmspace_free(vm2);
1053 uma_zfree(proc_zone, newproc);
1054 if ((flags & RFPROCDESC) != 0 && fp_procdesc != NULL) {
1055 fdclose(td, fp_procdesc, *fr->fr_pd_fd);
1056 fdrop(fp_procdesc, td);
1057 }
1058 atomic_add_int(&nprocs, -1);
1059 pause("fork", hz / 2);
1060 return (error);
1061}
1062
1063/*
1064 * Handle the return of a child process from fork1(). This function
1065 * is called from the MD fork_trampoline() entry point.
1066 */
1067void
1068fork_exit(void (*callout)(void *, struct trapframe *), void *arg,
1069 struct trapframe *frame)
1070{
1071 struct proc *p;
1072 struct thread *td;
1073 struct thread *dtd;
1074
1075 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED);
1076
1077 td = curthread;
1078 p = td->td_proc;
1079 KASSERT(p->p_state == PRS_NORMAL, ("executing process is still new"));
1080
1081 CTR4(KTR_PROC, "fork_exit: new thread %p (td_sched %p, pid %d, %s)",
1082 td, td_get_sched(td), p->p_pid, td->td_name);
1083
1084 sched_fork_exit(td);
1085 /*
1086 * Processes normally resume in mi_switch() after being
1087 * cpu_switch()'ed to, but when children start up they arrive here
1088 * instead, so we must do much the same things as mi_switch() would.
1089 */
1090 if ((dtd = PCPU_GET(deadthread))) {
1091 PCPU_SET(deadthread, NULL);
1092 thread_stash(dtd);
1093 }
1094 thread_unlock(td);
1095
1096 /*
1097 * cpu_fork_kthread_handler intercepts this function call to
1098 * have this call a non-return function to stay in kernel mode.
1099 * initproc has its own fork handler, but it does return.
1100 */
1101 KASSERT(callout != NULL, ("NULL callout in fork_exit"));
1102 callout(arg, frame);
1103
1104 /*
1105 * Check if a kernel thread misbehaved and returned from its main
1106 * function.
1107 */
1108 if (p->p_flag & P_KPROC) {
1109 printf("Kernel thread \"%s\" (pid %d) exited prematurely.\n",
1110 td->td_name, p->p_pid);
1111 kthread_exit();
1112 }
1113 mtx_assert(&Giant, MA_NOTOWNED);
1114
1115 if (p->p_sysent->sv_schedtail != NULL)
1116 (p->p_sysent->sv_schedtail)(td);
1117}
1118
1119/*
1120 * Simplified back end of syscall(), used when returning from fork()
1121 * directly into user mode. This function is passed in to fork_exit()
1122 * as the first parameter and is called when returning to a new
1123 * userland process.
1124 */
1125void
1126fork_return(struct thread *td, struct trapframe *frame)
1127{
1128 struct proc *p;
1129
1130 p = td->td_proc;
1131 if (td->td_dbgflags & TDB_STOPATFORK) {
1132 PROC_LOCK(p);
1133 if ((p->p_flag & P_TRACED) != 0) {
1134 /*
1135 * Inform the debugger if one is still present.
1136 */
1137 td->td_dbgflags |= TDB_CHILD | TDB_SCX | TDB_FSTP;
1138 ptracestop(td, SIGSTOP, NULL);
1139 td->td_dbgflags &= ~(TDB_CHILD | TDB_SCX);
1140 } else {
1141 /*
1142 * ... otherwise clear the request.
1143 */
1144 td->td_dbgflags &= ~TDB_STOPATFORK;
1145 }
1146 PROC_UNLOCK(p);
1147 } else if (p->p_flag & P_TRACED || td->td_dbgflags & TDB_BORN) {
1148 /*
1149 * This is the start of a new thread in a traced
1150 * process. Report a system call exit event.
1151 */
1152 PROC_LOCK(p);
1153 td->td_dbgflags |= TDB_SCX;
1154 if ((p->p_ptevents & PTRACE_SCX) != 0 ||
1155 (td->td_dbgflags & TDB_BORN) != 0)
1156 ptracestop(td, SIGTRAP, NULL);
1157 td->td_dbgflags &= ~(TDB_SCX | TDB_BORN);
1158 PROC_UNLOCK(p);
1159 }
1160
1161 /*
1162 * If the prison was killed mid-fork, die along with it.
1163 */
1164 if (!prison_isalive(td->td_ucred->cr_prison))
1165 exit1(td, 0, SIGKILL);
1166
1167 userret(td, frame);
1168
1169#ifdef KTRACE
1170 if (KTRPOINT(td, KTR_SYSRET))
1171 ktrsysret(SYS_fork, 0, 0);
1172#endif
1173}
struct proc proc0
Definition: init_main.c:109
struct proc * initproc
Definition: init_main.c:112
volatile int ticks
Definition: kern_clock.c:380
void startprofclock(struct proc *p)
Definition: kern_clock.c:589
void pdescfree(struct thread *td)
struct filedesc * fdshare(struct filedesc *fdp)
struct pwddesc * pdinit(struct pwddesc *pdp, bool keeplock)
struct pwddesc * pdshare(struct pwddesc *pdp)
struct filedesc * fdcopy(struct filedesc *fdp)
struct filedesc * fdinit(void)
void pdunshare(struct thread *td)
void fdunshare(struct thread *td)
void fdclose(struct thread *td, struct file *fp, int idx)
struct filedesc_to_leader * filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
struct pwddesc * pdcopy(struct pwddesc *pdp)
void fdescfree(struct thread *td)
void knote_fork(struct knlist *list, int pid)
Definition: kern_event.c:531
struct knlist * knlist_alloc(struct mtx *lock)
Definition: kern_event.c:2571
void exit1(struct thread *td, int rval, int signo)
Definition: kern_exit.c:222
void proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
Definition: kern_exit.c:1444
bitstr_t proc_id_reapmap
int fork1(struct thread *td, struct fork_req *fr)
Definition: kern_fork.c:853
void fork_rfppwait(struct thread *td)
Definition: kern_fork.c:808
SYSCTL_INT(_kern, OID_AUTO, lastpid, CTLFLAG_RD, &lastpid, 0, "Last used PID")
int sys_pdfork(struct thread *td, struct pdfork_args *uap)
Definition: kern_fork.c:122
static int randompid
Definition: kern_fork.c:208
static int fork_findpid(int flags)
Definition: kern_fork.c:257
__FBSDID("$FreeBSD$")
int sys_vfork(struct thread *td, struct vfork_args *uap)
Definition: kern_fork.c:149
static int sysctl_kern_randompid(SYSCTL_HANDLER_ARGS)
Definition: kern_fork.c:211
static void do_fork(struct thread *td, struct fork_req *fr, struct proc *p2, struct thread *td2, struct vmspace *vm2, struct file *fp_procdesc)
Definition: kern_fork.c:369
SYSCTL_PROC(_kern, OID_AUTO, randompid, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_MPSAFE, 0, 0, sysctl_kern_randompid, "I", "Random PID modulus. Special values: 0: disable, 1: choose random value")
void fork_return(struct thread *td, struct trapframe *frame)
Definition: kern_fork.c:1126
int sys_fork(struct thread *td, struct fork_args *uap)
Definition: kern_fork.c:104
bitstr_t proc_id_pidmap
int __exclusive_cache_line nprocs
Definition: kern_fork.c:195
SDT_PROVIDER_DECLARE(proc)
SDT_PROBE_DEFINE3(proc,,, create, "struct proc *", "struct proc *", "int")
bitstr_t proc_id_grpidmap
static int fork_norfproc(struct thread *td, int flags)
Definition: kern_fork.c:308
bitstr_t proc_id_sessidmap
int sys_rfork(struct thread *td, struct rfork_args *uap)
Definition: kern_fork.c:166
void fork_exit(void(*callout)(void *, struct trapframe *), void *arg, struct trapframe *frame)
Definition: kern_fork.c:1068
int lastpid
Definition: kern_fork.c:196
void prison_proc_hold(struct prison *pr)
Definition: kern_jail.c:2856
bool prison_isalive(const struct prison *pr)
Definition: kern_jail.c:3403
void kthread_exit(void)
Definition: kern_kthread.c:328
struct mtx __exclusive_cache_line Giant
Definition: kern_mutex.c:181
int priv_check_cred(struct ucred *cred, int priv)
Definition: kern_priv.c:151
void pstats_fork(struct pstats *src, struct pstats *dst)
Definition: kern_proc.c:1353
uma_zone_t proc_zone
Definition: kern_proc.c:138
void pargs_hold(struct pargs *pa)
Definition: kern_proc.c:1784
struct sx __exclusive_cache_line proctree_lock
Definition: kern_proc.c:135
struct mtx __exclusive_cache_line ppeers_lock
Definition: kern_proc.c:136
struct proclist allproc
Definition: kern_proc.c:133
struct mtx __exclusive_cache_line procid_lock
Definition: kern_proc.c:137
int kstack_pages
Definition: kern_proc.c:165
void proc_id_set_cond(int type, pid_t id)
Definition: kern_proc.c:348
int allproc_gen
Definition: kern_proc.c:3399
struct sx __exclusive_cache_line allproc_lock
Definition: kern_proc.c:134
void proc_unset_cred(struct proc *p)
Definition: kern_prot.c:2201
void proc_set_cred_init(struct proc *p, struct ucred *newcred)
Definition: kern_prot.c:2164
rlim_t() lim_cur(struct thread *td, int which)
void lim_fork(struct proc *p1, struct proc *p2)
int chgproccnt(struct uidinfo *uip, int diff, rlim_t max)
struct sigacts * sigacts_alloc(void)
Definition: kern_sig.c:4119
void sigacts_copy(struct sigacts *dest, struct sigacts *src)
Definition: kern_sig.c:4148
struct sigacts * sigacts_hold(struct sigacts *ps)
Definition: kern_sig.c:4140
void kern_psignal(struct proc *p, int sig)
Definition: kern_sig.c:2117
void sig_drop_caught(struct proc *p)
Definition: kern_sig.c:4165
int ptracestop(struct thread *td, int sig, ksiginfo_t *si)
Definition: kern_sig.c:2642
int sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
Definition: kern_sysctl.c:2136
int sysctl_handle_int(SYSCTL_HANDLER_ARGS)
Definition: kern_sysctl.c:1644
void microuptime(struct timeval *tvp)
Definition: kern_tc.c:406
void tidhash_add(struct thread *td)
Definition: kern_thread.c:1763
void thread_stash(struct thread *td)
Definition: kern_thread.c:573
void thread_cow_get_proc(struct thread *newtd, struct proc *p)
Definition: kern_thread.c:820
void proc_linkup(struct proc *p, struct thread *td)
Definition: kern_thread.c:468
int thread_suspend_check(int return_instead)
Definition: kern_thread.c:1365
void thread_single_end(struct proc *p, int mode)
Definition: kern_thread.c:1628
struct thread * thread_alloc(int pages)
Definition: kern_thread.c:746
int thread_single(struct proc *p, int mode)
Definition: kern_thread.c:1188
int thread_alloc_stack(struct thread *td, int pages)
Definition: kern_thread.c:773
bool thread_suspend_check_needed(void)
Definition: kern_thread.c:1319
int ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
Definition: kern_time.c:1118
linker_file_t * result
Definition: linker_if.m:148
void sched_fork(struct thread *td, struct thread *childtd)
Definition: sched_4bsd.c:789
void sched_fork_exit(struct thread *td)
Definition: sched_4bsd.c:1716
void sched_add(struct thread *td, int flags)
Definition: sched_4bsd.c:1285
int dummy
Definition: kern_fork.c:98
void kmsan_thread_alloc(struct thread *td)
Definition: subr_msan.c:439
void kmsan_mark(const void *addr, size_t size, uint8_t c)
Definition: subr_msan.c:547
int maxproc
Definition: subr_param.c:90
pid_t pid_max
Definition: subr_param.c:99
int hz
Definition: subr_param.c:85
int printf(const char *fmt,...)
Definition: subr_prf.c:397
uint16_t flags
Definition: subr_stats.c:2
void userret(struct thread *td, struct trapframe *frame)
Definition: subr_trap.c:99
int procdesc_falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags, struct filecaps *fcaps)
Definition: sys_procdesc.c:237
void procdesc_new(struct proc *p, int flags)
Definition: sys_procdesc.c:212
void procdesc_finit(struct procdesc *pdp, struct file *fp)
Definition: sys_procdesc.c:253
void proc_set_traced(struct proc *p, bool stop)
Definition: sys_process.c:734
void vrefact(struct vnode *vp)
Definition: vfs_subr.c:3075
int fd